Abstract

We have quantified unintentional indium incorporation in GaAs grown by molecular beam epitaxy in a variety of commercial systems. We find that the unintentional indium density in the epitaxial GaAs is more a function of mounting technique and prior machine history than of the manufacturer’s design. The indium densities detected in the epitaxial GaAs for substrates that only partially obscure an indium‐bearing mount are equal to levels reported to result in minimum defect densities and narrowest photoluminescencelinewidths in In‐doped GaAs.